A known technique for ejecting a liquid material in the form of flying droplets employs a retracting and advancing plunger. The plunger is quickly accelerated to advance and then abruptly stopped by abutting it against a valve seat. Upon the abrupt stop, an inertial force is applied to the liquid material present in front of the plunger, thus causing the liquid material to eject in the form of flying droplets under the action of the inertial force. With such a known technique, however, because the inertial force required for ejecting a liquid material in the form of flying droplets is obtained by abutting a moving solid plunger against a stationary solid valve seat and momentarily stopping the movement of the plunger, there arise problems that the plunger and the valve seat are seriously damaged by the abutting. Another problem is that a damaged member is mixed into the liquid material to melt therein.
With the view of solving those problems, the applicant previously proposed a technique wherein, after bringing a distal end surface of a plunger for delivering the liquid material into close contact with the liquid material, the plunger is accelerated to advance at high speed, and subsequently a plunger driving means is abruptly stopped to suddenly stop the plunger advancing at high speed without abutting it against a valve seat, so that an inertial force is applied to the liquid material present in front of the plunger and the liquid material is ejected in the form of flying droplets by the applied inertial force (Japanese Patent Application No. 2001-319074).